Pitometer.



T. HAVILL.

PITOMETBR.

AfiPLIGATION FILED APR.22, 1912.

Patented Mar. 3, 191 1.

- oral outline a pressure gage used in con-- incense.

pensed with.

UNITE 11;

HAROLD '1'. HAVILL, or new roux, n. r,

ASSIGNOR 0F ONE-FOURTH TO ECi-IQERFEl-U.

HAVILL, OF NEVJ' YORK, N. Y.

PITOMETER.

Patented llfllar. atom.

Application filed Apriljefz, 1912. Serial No. 892,293.

To call whom, it may concern Be it known that I, HAROLD T. HAVILL, a citizen of the United States, and a resident of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Pitometers, of which the following is a full and clear specification, the particular novel features ol -my invention being set forth in the annexed claim.

My invention relates to means for measuring the fluid pressure at two points in the direction of the flow of the,tube of varying diameter, through which the fluid flows. Tubes of the character which I employ are generally known at Venturi tubes and they have been employed for a similar purpose in a form in which a section of the water" main itself is formed as a Venturr tube and whereby the pressure is measured at the wide end and at the contracted end of the tube. The disadvantages of such an rangement are that it is only possible to measure the flow of water at that particular point of the system and that unless such a tube is inserted at every point where it might be dcsirable later to measure the flow of water, when the mains are laid, it is impossible later to ascertain the flow of water. Therefore the Venturi tube has not hereto- :lore been employed tor subsequently ascertaining the flow of water in places of the tem where the leakages a re suspected, which cannot be ascertained except by measuring the flow of water in the pipe"and the amount of water drawnat the regular points of drainage. 1

My instrument is portable and capable of indicating diiierences of pressure between the two ends of a Venturi tube with an ordinary pressure gage so that cumbersome measuring devices such U-tubes filled with 2. quid of light specific gravity can he d1sl'lin Tu We accompanying drawings I have 35 l ustra ted my 1nvent1on.

in these drawings: Figure 1 shows a lo'ngitudinal vertical section through the en,

tire dm-ticc as adjusted in a Water main in approximately full size. Fig. 2 is a plan view of" the cntm'i tube which I employ, in larger scale, and Fig. 3 represents in gennection with the pitometer..

The general construction of the apparatus is asfollows.

1 indicates a portion of the water main in which the flow of water is to be measured.

2 is the cock which remains inserted or which can be inserted in pipes at any point where the flow of water is to be measured. The manner of subsequently attaching this fitting to water pipes is well known in the art so that description thereof is omitted herein.

The valve member 3 of the cock has a boring of suitable size to admit a tube 4 within which the two pipes 5 and 6 are disposed which are at their upper ends connected to any suitable pressure gagecapable of indicating the diilercnce in pressure in the two tubes, as for instance shown in general outline at 15 in Fig. 3. Cock 2 carries thread ed to its upper end the auxiliary chamber 2' provided with a stulling box 8 at its upper end through which the lower end of tube lis first inserted before valve member 3 of the cock is opened. After the gland 9 of the stufling box is properly tightened the cock is opened and the tube inserted through 'alvc member 3 down into the water main. By this expedient which is known in the art, unnecessary leakage of water is avoided while the tube 4; is inserted. Pipes 5 and 6 extend beyond the lower end of tube 4-. and carr I together at their lower ends Venturi tube 10. This tube has its wide portion 11, at the end which faces the ontlowiug water and its contracted portion 12 at the opposite end, care being taken that when tube t is inserted the longitudinal axis of the Venturi tube coincides with theclirection of the flow of water. Pipe 5 communicates with the wide portion 11 ofthc Venturi tube 'and pipe 6 communicates with the contracted portion 12 of the Venturi tube. Now, when the tube is inserted as previously described, and part of the ontlowing water (indicated by the arrow in Fig. 1) passes through the Venturi tube there will be a certain pressure p in its portion 11 which is communicated to pipe 5. Part of the potential energy of the water when forced through the tube into the contracted portion i2 is transformed into kinetic energy so that the pressure in conlxracted portion 12 is smaller than This pressurcfis communicated to pipe 6. As above referred to the diflierence in pressure between the two pipes is measured at their outer ends by a suitable gage l5. Pitometers are known in the art in which for instance the lower end of pipe 5 is bent to ward the onflo'wing water and the lower end of pipe 6 bent in the direction of the flow of the Water, so that the difi'ereiice in pres sure caused by the impact of the onfiowing water and the vacuum formed by the oif flowing water can be measured at the outer on of these two pipes. This difierence in pressureis so slight that only very sensitive instruments such as for instance U-tubes filled with specifically very light fluid can be used to give fairly good results. My present instrument has the advantage over instruments such as referred to above, that the differences in pressure at the two ends of the Venturi tube are so great that a coarser instrument such as a pressure gage, will easily indicate them with sufficient exctness 'to calculate therefrom the flow of water in the pipe in the usual manner known in the art.

may be stated that of course pipes 5 and 6, where they leave the upper end of tube st are led through small stufiing boxes 5 and 6 to prevent escape of water to the outside.

It nfay be also stated that while I have shown a convenient outside shape of the body 10 which contains the boring and which forms the Venturi tube this form is in no way meant to indicate the only form feasible for my purpose. Also. while I have shown in Fig. 1 the contracted portion 12 of the Venturi tube straight it may also flare outwardly as for instance shown in Fig. 2 at 12 \Vhat I claim is:

A portable pitoineter on the Venturi principle, comprising a suitable length of tubing forming the shell of the pitonieter, a Venturi tube located adjacent to one end of said tubing having a pipe late'ally connected adjacent to either of its ends, said pipes being located inside of said shell tubing and leading to its other end.

HAROLD T. HAVILL. Witnesses:

XVM. A. COURTLAND, H. ALF an JANICE. 

